Bag filling and sealing machines



Sept. 23, 1558 c. BERG BAG FILLING AND SEALING MACHINES 2 Sheets-Sheet 1Filed March 5. 1958 INVENTOR. CARL BERG uJM HIIIE EO AT TORNEYS Sept.23, 1958 C. BERG BAG FILLING AND SEALING MACHINES 2 Sheets-Sheet 2 FiledMarch 5, 1958 FIG. 8

INVENTORQ CARL Bans I. I Y I ATTORNEYS United States Patent fifice2,852,898 Patented Sept. 23, 1958 BAG FILLING AND SEALING MACHINES CarlBerg, Minneapolis, Minn., assignorto Super Valu Stores, Inc., Hopkins,Minn., a corporation of Delaware Application March 1958, Serial No.719,359 3 Claims. (Cl. 53-182) My invention relates generally to bagfilling and clo sure forming machines and more particularly to machinesfor forming, filling and sealingbags formed from thermoplastic sheetmaterial.

Machines of the class immediately above described comprise cooperatingheads movable toward and away from each other in a horizontal plane andintersecting the path of travel of a tubular thermoplastic bag-formingmember. One of said heads is provided with vertically spacedhorizontally extended heater elements for simultaneously sealing the topof a filled bag and the bottom of the next succeeding bag when the headsare brought into sealing engagement. Furthermore, one of the heads isprovided with a cutter blade for transversely severing the tubularmember intermediate the heating elements during the sealing operation.In this manner, the filled sealed bags are successively separated fromthe tubular member during each reciprocation of the heads. In practice,I have found that only too frequently the thermoplastic material sticksto the heating element during the top sealing operation on the filledbag. As a result, the filled bag is not discharged or released from theheads during the cycle of reciprocal movements thereof and the machinebecomes jammed with a consequent loss of product and time.

The primary object of my invention is the provision of novel means forpositively separating filled bags from the heating elements responsiveto movements of said heads away from each other whereby to avoid jammingof the machine and to bring about uninterrupted operation thereof.

A further object of my invention is the provision of a device of theclass immediately above described which incorporates a minimum ofworking parts and hence is inexpensive to produce and to maintain.

A still further object of my invention is the provision of a device ofthe class above described which is positive in its action and rugged anddurable in construction.

The above and still further objects of my invention will become apparentfrom the following detailed speci fication, appended claims and attacheddrawings.

Referring to the drawings wherein like characters indicate like partsthroughout the several views:

Fig. 1 is a fragmentary view in side elevation of a conventional bagforming, filling and sealing machine illustrating my novel inventionattached thereto, some parts being broken away and some parts shown insection;

Fig. 2 is a fragmentary View in side elevation of some of the structureof Fig. 1 showing a different position of some of the parts and someadditional parts being added;

Fig. 3 is a view in front elevation of one of the bag sealing heads ofthe machine of my invention; and

Fig. 4 is a fragmentary view corresponding to a portion of Fig. 1 butshowing a difierent position of some of the parts.

Referring with greater particularity to the drawings, the numeral 1indicates in its entirety a machine of the conventional type for theforming, filling and sealing of bags from thermoplastic sheet material.The machine 1 includes an upright supporting member 2 to which isattached, by means not shown, a vertically disposed depending former andfiller tube 3 formed from suitable metal or the like and as shown havinga circular crosssection. Fed onto the forming and filling tube 3, from asource not shown such as a spool, is an elongated strip 4 ofthermoplastic material, such as cellophane or polyethylene. As shownparticularly in Fig. 2, the strip 4 is caused to be wrapped about thetube 3 longitudinally thereof by passing same between the tube 3 and acircumferentially spaced concentric sleeve 5. Thereafter, the overlappededges 6 of thestrip 4 are sealed by suitable heating means 7 comprisingheated rollers or the like 8, whereby to form a continuous bag formingtube 9.

Below the combination forming, filling tube 3 and intersecting the pathof travel of the tubular bag forming member 9 in its downward course,are a pair of cooperating heads 10 and 11 which are suitably mounted formovements toward and away from each other in a horizontal plane bymechanism, not shown. As shown, the head 10 has a pair of verticallyspaced horizontally extended heating elements 12 and 13 of conventionaldesign which forcefully engage opposed shoulders 14 and 15 respectivelycarried by the head 11, the members 12, 14 cooperating to seal the topof a filled bag 16 and the members 13 and 15 cooperating tosimultaneously seal the bottom of the next succeeding bag 17, when theheads 14), 11 are moved into engagement with each other, as shown inFig. 1.

A horizontally extended cutter blade 18, shown as being carried by thehead 11, is positioned between the heating elements 12, 13 and seversthe tubular member 9 to separate the filled bag 16 from the immediatelysucceeding bag 17.

In order to positively assure separation of the filled bags 16 from theheating element 12 during movements of the heads 10, 11 away from eachother, so as to assure uninterrupted operation of the machine 1, Iprovide a pad 19 which is carried by the head 10 in downwardly spacedrelation to the heating element 12 and which engages the side of thefilled bag 16 adjacent the upper end portion thereof, as shown inFig. 1. During sealing movements of the elements 12, 14, the pad 19cooperates with a similar pad 20 carried by the head 11 and engageablewith the opposite side of the bag 16 adjacent its upper end portion, allin a conventional manner. However, the pad 19 is secured to the head 10through the medium of an arm 21 connected thereto, as at 22, and ahorizontally disposed rock shaft 23 that is journaled in bearingbrackets 24 secured to the head 10 as indicated at 25 in Fig. 4. Rigidlysecured to the rock shaft 23 is a crank arm 26 to the outer end of whichis pivotally secured, as at 27, the outer end of an armature 28 of asolenoid 29 secured to the head 10. The solenoid 29 is interposed in anelectrical circuit 30 including a control switch 31, the operatingbutton 32 of which is positioned to be engaged by the head 10 uponrelative movement thereof away from the head 11 whereby the solenoid 29is energized, as indicated in Fig. 4. As there shown, when the topportion of a filled bag 16 becomes adhered to the heating element 12 orother adjacent portions of the head 10, energization of the solenoid 29by closing of the switch 31 causes the pad 19 to swing laterally anddownwardly into the path of travel of the tubular member 9 and filledbag 16, thereby forcefully removing the filled bag 16 from the head 10,as indicated by dotted lines, whereby it drops vertically downwardlyinto a guide trough 33 or the like and hence onto a conventionalconveyor belt or the like 34.

My invention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the above objects and while Ihave shown a preferred embodiment thereof, I wish it to be specificallyunderstood that same is capable of modification without departure fromthe scope and spirit of the appended claims.

. What I claim is: I

1. An attachment for machines for forming, filling and sealing bagsformed from thermoplastic sheet material in tubular form, said machinesincluding cooperating heads movable toward and away from each other in ahorizontal plane and intersecting the path of travel of a tubularbag-forming member, sealing means on said heads, said means including apair of vertically. spaced horizontally extended heating elements on oneof said heads for simultaneously sealing the top of a filled bag and thebottom of the next succeeding bag, a cutter blade carried by one of saidheads and positioned to transversely sever said tubular memberintermediate said heating elements when said heads are brought intosealing engagement, said attachment comprising a pad engageable with oneside of a filled bag adjacent its upper end portion when said heads arein sealing engagement, means mounting said pad for swinging movementslaterally and downwardly into said path of travel, and means forimparting said swinging movements to said pad responsive to movements ofsaid heads away from each other whereby to positively separate said bagfrom said No references cited.

